All those fancy new school playgrounds you’ve been seeing pop up behind schools in the borough? They’re part of a massive, ambitious plan by Mayor Bloomberg and the NYC Parks Department to revamp, or create from scratch, 256 playgrounds by 2013.

The twist: during the creation of these fancy, beautiful new outdoor spaces, students of the school are given a real, powerful voice in choosing what the site will look like.

Here’s how the entire process works.

First, representatives from Parks select a site. Whether a school gets its playground rebuilt a bit, or completely overhauled new, is dependent on a number of factors involving school size, location, and public area around it.

The newest site chosen was P.S. 76, on Adee Avenue.

Mary Alice Lee, director of the playgrounds program of Trust for Public Land, explained that although the actual construction of the playgrounds is remarkably quick once it begins, the planning starts years in advance. With P.S. 76, the first meeting was back in April of 2008, though building on the site did not begin until June 2010.

“We started by having three separate meetings with P.S. 76,” said Lee, who noted that TPL has had the main role in 28 of these playgrounds, but not in this case.

With P.S. 76 and others, TPL helps out in an advisory role, but Parks handles most of the process.

“We had the initial site meeting, where we met with the principal, staff, and community members the school chooses to include, and we talked to them about how they use the yard now. Then, once it’s all set to move forward, the students enter the process,” said Lee.

When TPL is involved, the student-led design process takes three months. But when the Parks Department is handling the project — dealing with less of a budget — all of that happens in one day. “One very long day,” joked Violette Rychlicki, a design project manager for Parks.

“We introduce the students to concepts of design principles, and we do hands-on stuff where we go out into the schoolyard and do some measuring, and talk about the wind, the sun, the rain, and the particular challenges of their site,” she said. Then, after they’ve seen it all, they head back inside to begin planning the playground. It’s a process in which kids are given a voice they aren’t used to having.

“They really do have the say,” said Rychlicki. “They vote on the elements that are important to them, and these are often the same across the board, like a basketball court, a track, a jungle gym, water fountains. But there are cases where kids come up with just incredible things.”

“Maybe they’re especially interested in music, or dinosaurs, and they come up with a truly inventive element to include in their schoolyard,” she explained further. “The field is wide open of what they can do with it. They can invent games, and it becomes an element of free play.”

Louise Sedotto, principal of P.S. 76, said the process has completely impressed her. “It was really exciting because the kids got to formulate it with legos and blueprints, and they came up with great stuff,” she recalled. “They wanted a track, synthetic turf, tables with printed games, a volleyball court, a basketball court, and they got it all. Plus they came up with adding a world map, a nice area for jumping rope, and a walking trail all along the building.”

Sedotto voiced what are likely the feelings of many other principals who have been lucky enough to have their playgrounds transformed: “I like the whole idea and initiative behind this,” she said, “in terms of the Mayor wanting every kid to have a playground within 10 minutes walking distance.”

Once construction actually begins, the process is “remarkably fast,” as Rychlkicky put it. First, builders plop down the jungle gym structure, a small gazebo, and any tables or water fountains on the empty concrete. Then, a colorseal of bright paints is put in atop the entire space. This all takes only a few weeks, before a track and synthetic turf field are lain in.

Finally, basketball hoops are installed.

Once it’s ready, the students themselves are let loose to paint a mural if they choose. And then it’s open for play.

The playground at P.S. 76 will be finished over the summer.

In a ribbon-cutting ceremony, Sedotto said they would dedicate the park to one of their school aids who worked at P.S. 76 for 13 years and recently passed away at a young age.